ICRISAT Archival Report 2006 - The seedlings of success in the ...

plots. The results clearly suggest the usefulness of combining insect-resistant varieties with insecticides for
management of H. armigera.
Synergism of host plant resistance to Helicoverpa with insecticides its implications for ETLs in chickpea: We
evaluated the effect of different protection regimes on H. armigera-resistant (ICC 506 and ICCV 10) and susceptible
(ICC 3137 and ICCC 37) genotypes of chickpea to quantify the contribution of host plant resistance in management
of H. armigera. The plots were sprayed at vegetative, flowering, and podding stages with methomyl. There were
three replications in a factorial design. In the untreated control plots, there were 37.7, 86.7, 11.7, 32.3, and 26.0
larvae per 5 plants in Annigeri, ICC 3137, ICC 506, ICCC 37, and ICCV 10, and the pod damage was 15.3, 29.6,
5.2, 15.8, and 13.55%, respectively. Grain yield was 1431 to 1704 kg ha -1 in Annigeri, ICC 506, ICCV 10, and
ICCC 37 compared to 926.1 kg in ICC 3137. In the plots that were protected at the vegetative and flowering stages,
the pod damage was 0.6% in ICC 506, 8.3% in Annigeri, and 11.2% in ICCV 10 as compared to 60.5% in ICC
3137, suggesting that host plant resistance in combination insecticides is quite effective in minimizing the pod borer
damage. The plots that were protected at the vegetative, flowering, and podding stages had 1.7, 4.7, 1.3, 2.3, and 1.3
larvae per 5 plants, and suffered 9.5, 5.7, 0.1, 2.4, and 4.8% pod damage in Annigeri, ICC 3137, ICC 506, ICCC 37,
and ICCV 10, respectively, indicating that three applications of insecticides at the critical stages provides a good
protection against H. armigera. The grain yield was 1879kg ha -1 in ICCV 10, followed by 1924 kg in Annigeri, and
1663 kg in ICC 506 as compared to 1376 kg in case of ICC 3137. Further analysis is in progress to compute the
economic thresholds for cultivars with different levels of resistance/susceptibility to H. armigera.
HC Sharma
Milestone: Tri-trophic interactions involving insects, host plants, and natural enemies for effective pest management
studied (HCS) 2009
Identification of potential natural enemies of Helicoverpa in chickpea and pigeonpea eco-systems: Natural
enemies of H. armigera have been collected from different eco-systems. Cultures of the parasitoids, Campoletis
chlorideae, and Cotesia sp.; and the predators, Cheilomenes sexmaculatus, and Chrysoperla carnea have been
established in the laboratory for further studies on bio-efficacy, and develop protocols for mass multiplication of
these natural enemies for use in studies on effects of transgenics on non-target organisms, and biological control of
H. armigera.
HC Sharma
Relative efficiency of Campoletis chlorideae to parasitize different insect hosts and Helicoverpa armigera
larvae on different host plants: Helicoverpa armigera is a serious pest of cotton, grain legumes, and cereals.
Complex intercropping systems and large scale deployment of Bt-transgenic crops with resistance to H. armigera
have potential consequences for the development and survival of C. chlorideae. Therefore, we studied the tritrophic
interactions of C. chlorideae involving eight insect host species and six host crops under laboratory conditions. The
recovery of H. armigera larvae following release was greater on pigeonpea and chickpea as compared to cotton,
groundnut, and pearl millet. The parasitism by C. chlorideae females was least with reduction in cocoon formation
and adult emergence on H. armigera larvae released on chickpea. Host insects also had significant effect on the
development and survival of C. chlorideae. The larval period of C. chlorideae was prolonged by 2 to 3 days on
Spodoptera exigua, Mythimna separata, and Achaea janata as compared to H. armigera, H. assulta, and S. litura.
Maximum cocoon formation and adult emergence were recorded on H. armigera (82.4 and 70.5%, respectively)
than on other insect hosts. This information can be used to devise appropriate cropping systems to encourage the
activity of natural enemies for biological control of insect pests.
MK Dhillon and HC Sharma
Output target 6C.6: New technologies evaluated, disseminated and their impact documented
Activity 6C.6.1: Exchange improved technologies and new knowledge with ARIs, NARs, NGOs, private sector
and farmers’ groups
Milestone: Pest management packages developed and disseminated through mass media, literature and e-learning
(GVRR/OPR/HCS/CLLG/SNN/SP) Annual
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